[Radiance-general] Illuminance values

[Lars O. Grobe]

Hi...
> I am simulating to find illuminance values for different angles of
> Venetian blinds, Using Mkillum.. Do we need to consider Blinds as part
> of the Luminous plane generated by mkillum..? We are getting better
> results when using just a plane polygon as Luminous secondary source
> as compared to when we include Blinds in the fenestration system as
> luminous plane. ( comparing two different systems of blinds of similar
> angles and characteristics.)
If I understand you right - are you asking wether to replace the each
blind's surface by a mkillum-generated illum??? This makes no sense -
you have aluminium blinds, and no light will pass through a blind. This
must lead to really funny results.

Mkillum has been written to precalculate the effect of compex
fenestration such as blinds. You calculate a light source on the inside
of the complex fenestration using mkillum, so that during your (rpict or
rtrace) rendering, the light source for ambient calculations is not
obstructed. The reasons for this are explained in detail in the book
"Rendering with Radiance".

In your case there are only two reasonable options as far as I
understood so far. Either render without mkillum, but very(!!!)  high
quality settings for ad, as, aa, ab (which will take a long time), or
seal your complete fenestration system with mkillum-generated illum
surface(s) as explained in the book.


CU Lars.